Question

一个C语言程序输出序号和单词,#include #include #define MAX 40int main(void

Answer 1

#include

#include

#define MAX 40

int main(void)

{

FILE *fp;

char words[MAX];

int wordct = 0;

if ((fp = fopen("wordy","a+")) == NULL) //打开文件,是指针fp指向文件wordy

{

fprintf(stderr,"Can't open "words" file.n");

exit(1);

}

/* determine current number of entries */

rewind(fp); //rewind()是一个反绕函数,作用是使指针回到文件的开头,在对文件读写的过程中,指针是一直变化的,但是这个函数会把指针重新置在文件的开头

while (fgets(words,MAX - 1,fp) != NULL) // 统计文件中单词个数

wordct++;

rewind(fp);

puts("Enter words to add to the file.Enter one word per line,and ");

puts("press the Enter key at the beginning of a line to terminate.");

while (gets(words) != NULL && words[0] != ' ')

fprintf(fp,"%d:%sn",++wordct,words); //追加新单词到文件中,并标注序号wordct

puts("File contents:");

rewind(fp); /* go back to beginning of file */

while (fgets(words,MAX - 1,fp) != NULL)

fputs(words,stdout);

if (fclose(fp) != 0)

fprintf(stderr,"Error closing filen");

return 0;}